Great bra fitting tips from Lingerie Buyers Ali Cudby as featured in Cosmopolitan magazine.

Read these practical hints and tips on how to buy a great fitting bra.

Ignore Your Size

Every lingerie brand fits a bit differently—just because you wear a 34B at Victoria’s Secret doesn’t mean you’re a 34B across the board. Plus, a woman’s bra size changes at least six times over the course of her life (not including pregnancy and weight gain). So always try on a few sizes from a new company to find the right fit—or ask someone in the store to measure you.

Avoid the No.1 Mistake

The most common error women make when buying bras is getting a too-big band. If the band is loose, it rides up in the back, causing the front of your bra to drag down. Saggy cleavage = not hot. An oversized band also creates faux back fat—it moves around rather than lying flat, creating bumps and bulges.

Check Your Back

The band carries 85 percent of the weight of your breasts, so it should be firm, anchored, and horizontal across your frame. Slide a couple of fingers under the band and pull it away from your body—it should move no more than an inch or two. And when you look in the mirror, you want the bottom of the band in the back to be parallel to the underside of your breasts in the front.

Adjust Your Cups

Band size and cup size are interrelated, so if you go down a band size, you usually need to go up a cup to get the same volume. (For example, a 34B has the same amount of cuppage as a 32C.) Push against the underwire on the side of your bra, right under your armpit. You want it to press into your ribs, not delicate breast tissue—increase your cup if that’s the case. Also, the center of the bra between the two cups should be flush against your sternum. If it’s popping out, that’s another sign you need a bigger cup.

Be a Smooth Operator

You want a smooth line from the bottom of your breasts to the top. If you notice any wrinkling, that means the cups are too big. If your boobs are spilling over the top, bottom, or sides, you need to go up a cup size.

Take a Load Off

Many women carry way too much of the weight of their breasts in their shoulders. But straps aren’t intended to bear weight; they should be just long enough to keep your bra in place without slipping off—so lengthen those straps. Your band should be what’s supporting the load.

Loosen Up

Aim to buy your bra on the loosest hook. Since the fabric naturally gives over time, as the bra stretches you can move up a hook.